The evidence for the Big Bang

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Table, Evidence for the Big Bang (NASA, ESA), with columns Observation, What it shows

   Galaxy redshifts grow with distance, space is expanding; microwave background at about 2.7 K, a hot, dense early universe; mostly hydrogen and helium, a little lithium, early element-making.

2. 1.

   Which observation shows that space is expanding, by Ari's reading?

   • The microwave background's measured temperature
   • The amount of helium
   • Stars twinkling at night
   • Galaxy redshifts that grow with distance
3. 2.

   Which observation shows the early universe was hot and dense, by Bo's reading?

   • The cosmic microwave background
   • Galaxy redshifts
   • Light from nearby stars
   • The Milky Way's spiral arms
4. 3.

   Timeline from the Big Bang with an early mark. About when was the cosmic microwave background released, by Jun's reading (NASA)?

   • About 380,000 years after the Big Bang
   • About 13.8 billion years after the Big Bang
   • Recently, given off by the stars in our own galaxy
   • When the Sun formed
5. 4.

   Thermometer scale from 0 K to 10 K. What is the cosmic microwave background's temperature today, by Luz's reading (ESA Planck)?

   • About 3,000 K, as when it was released
   • About 2.7 K
   • About 5,800 K, like the Sun
   • About 270 K
6. 5.

   Why is the background light now in microwaves, not visible light, by Milo's reading?

   • It was squeezed to shorter wavelengths
   • It started as microwaves
   • Expansion stretched it to longer wavelengths
   • It comes from cold stars

7. Table, Evidence for the Big Bang (NASA, ESA), with columns Observation, What it shows

   Galaxy redshifts grow with distance, space is expanding; microwave background at about 2.7 K, a hot, dense early universe; mostly hydrogen and helium, a little lithium, early element-making.

8. 6.

   Which elements does the Big Bang model say formed in the first minutes, by Noah's reading (NASA)?

   • Just iron and gold
   • The whole periodic table, formed in one blast
   • Carbon, oxygen and iron
   • Hydrogen, helium and a little lithium
9. 7.

   Pie chart of atoms in the oldest gas (sources give 92 to 95% hydrogen). Most atoms in the oldest gas clouds are which elements, by Pia's reading?

   • Carbon, then oxygen
   • Iron, then nickel
   • Equal amounts of each element
   • Hydrogen, then helium
10. 8.

    Why do the amounts of hydrogen and helium count as evidence, by Ren's reading?

    • They show where stars formed first
    • They show galaxies are moving apart
    • They match what the early universe should have made
    • They show the theory is a guess
11. 9.

    Timeline ruler in billions of years. About how old is the universe, by Tala's reading (NASA, ESA Planck)?

    • About 138 billion years
    • About 13.8 million years
    • About 4.6 billion years, Earth's age
    • About 13.8 billion years
12. 10.

    Three evidence lines pointing to one explanation. In science, what does it mean to call the Big Bang a theory, by Esme's reading?

    • A guess with no evidence
    • An untested idea that scientists have not checked against anything
    • A well-tested explanation that fits many observations
    • A law that cannot be revised